Beam management enhancements for mmwave operations

ABSTRACT

Beam management enhancements for advanced millimeter wave (mm Wave) operations are disclosed. As a part of channel state information (CSI) reporting configuration, a user equipment may include an interference plus noise measurement of beams for consideration in beam management. The UE measures a set of signaling resources of each beam for power contribution and interference plus noise. According to the particular configuration, the UE may rank all of the available beams into a subset of the highest ranked beams, ranked either by the interference plus noise measurement, by the power contribution metric, or by a combination of both. The UE reports an identification of the subset to the serving base station which determines the beam to use for subsequent communications with the UE.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 62/755,248, entitled, “BEAM MANAGEMENT ENHANCEMENTS FORADVANCED MMWAVE OPERATIONS,” filed on Nov. 2, 2018, which is expresslyincorporated by reference herein in its entirety.

BACKGROUND Field

Aspects of the present disclosure relate generally to wirelesscommunication systems, and more particularly, to beam managementenhancements for millimeter wave (mm Wave) operations.

Background

Wireless communication networks are widely deployed to provide variouscommunication services such as voice, video, packet data, messaging,broadcast, and the like. These wireless networks may be multiple-accessnetworks capable of supporting multiple users by sharing the availablenetwork resources. Such networks, which are usually multiple accessnetworks, support communications for multiple users by sharing theavailable network resources. One example of such a network is theUniversal Terrestrial Radio Access Network (UTRAN). The UTRAN is theradio access network (RAN) defined as a part of the Universal MobileTelecommunications System (UMTS), a third generation (3G) mobile phonetechnology supported by the 3rd Generation Partnership Project (3GPP).Examples of multiple-access network formats include Code DivisionMultiple Access (CDMA) networks, Time Division Multiple Access (TDMA)networks, Frequency Division Multiple Access (FDMA) networks, OrthogonalFDMA (OFDMA) networks (e.g., a Long Term Evolution (LTE) system, or aNew Radio (NR) system), and Single-Carrier FDMA (SC-FDMA) networks. Awireless multiple-access communications system may include a number ofbase stations (e.g., a gNB, TRP, eNB) or other network access networknodes, each simultaneously supporting communication for multiplecommunication devices, which may be otherwise known as user equipment(UE).

In some wireless systems, base stations and UEs may communicate usingdirectional transmissions (e.g., beams), where beamforming techniquesmay be applied using one or more antenna arrays to generate beams indifferent directions. For example, a base station may transmit downlinkcommunications (e.g., synchronization signals, signals, data signals,etc.) to a UE using a transmit beam oriented in a particular direction,and the UE may in turn receive the downlink communications using areceive beam oriented in a direction opposite to the transmit beam. Invery high frequency systems a base station may transmit using narrowbeams to overcome path loss. A UE may be able to receive on manysuitable downlink beams from one or more base stations, Searching andtracking a large number of beams increases complexity and consumes modemand RF power. It may thus be desirable to improve techniques fordownlink beam selection in beamformed communication systems.

SUMMARY

In one aspect of the disclosure, a method of wireless communicationincludes receiving, at a user equipment (UE), a channel stateinformation (CSI) reporting configuration message from a serving basestation, wherein the CSI reporting configuration message identifies aset of CSI resources for reporting CSI on a plurality of beams by theUE, measuring, by the UE, an interference plus noise metric of a firstsignaling resource of each beam of the plurality of beams, measuring bythe UE, a power contribution metric of a second signaling resource ofeach beam of the plurality of beams, ranking, by the UE, the pluralityof beams based on a ranking parameter, wherein the ranking parameterincludes one of: the interference plus noise metric, or the powercontribution metric, selecting, by the UE, a subset of highest rankedbeams according to the ranking, and transmitting, by the UE,identification of the subset of highest ranked beams to the serving basestation via the set of CSI resources.

In an additional aspect of the disclosure, an apparatus configured forwireless communication includes means for receiving, at a UE, a CSIreporting configuration message from a serving base station, wherein theCSI reporting configuration message identifies a set of CSI resourcesfor reporting CSI on a plurality of beams by the UE, means formeasuring, by the UE, an interference plus noise metric of a firstsignaling resource of each beam of the plurality of beams, means formeasuring by the UE, a power contribution metric of a second signalingresource of the each beam of the plurality of beams, means for ranking,by the UE, the plurality of beams based on a ranking parameter, whereinthe ranking parameter includes one of: the interference plus noisemetric, or the power contribution metric, means for selecting, by theUE, a subset of highest ranked beams according to results of the meansfor ranking, and means for transmitting, by the UE, identification ofthe subset of highest ranked beams to the serving base station via theset of CSI resources.

In an additional aspect of the disclosure, a non-transitorycomputer-readable medium having program code recorded thereon. Theprogram code further includes code to receive, at a UE, a CSI reportingconfiguration message from a serving base station, wherein the CSIreporting configuration message identifies a set of CSI resources forreporting CSI on a plurality of beams by the UE, code to measure, by theUE, an interference plus noise metric of a first signaling resource ofeach beam of the plurality of beams, code to measure by the UE, a powercontribution metric of a second signaling resource of each beam of theplurality of beams, code to rank, by the UE, the plurality of beamsbased on a ranking parameter, wherein the ranking parameter includes oneof: the interference plus noise metric, or the power contributionmetric, code to select, by the UE, a subset of highest ranked beamsaccording to execution of the code to rank, and code to transmit, by theUE, identification of the subset of highest ranked beams to the servingbase station via the set of CSI resources.

In an additional aspect of the disclosure, an apparatus configured forwireless communication is disclosed. The apparatus includes at least oneprocessor, and a memory coupled to the processor. The processor isconfigured to receive, at a UE, a CSI reporting configuration messagefrom a serving base station, wherein the CSI reporting configurationmessage identifies a set of CSI resources for reporting CSI on aplurality of beams by the UE, to measure, by the UE, an interferenceplus noise metric of a first signaling resource of each beam of theplurality of beams, to measure by the UE, a power contribution metric ofa second signaling resource of each beam of the plurality of beams, torank, by the UE, the plurality of beams based on a ranking parameter,wherein the ranking parameter includes one of: the interference plusnoise metric, or the power contribution metric, to select, by the UE, asubset of highest ranked beams according to execution of theconfiguration of the at least one processor to rank, and to transmit, bythe UE, identification of the subset of highest ranked beams to theserving base station via the set of CSI resources.

The foregoing has outlined rather broadly the features of examplesaccording to the disclosure in order that the detailed description thatfollows may be better understood. Additional features and advantageswill be described hereinafter. The conception and specific examplesdisclosed may be readily utilized as a basis for modifying or designingother structures for carrying out the same purposes of the presentdisclosure. Such equivalent constructions do not depart from the scopeof the appended claims. Characteristics of the concepts disclosedherein, both their organization and method of operation, together withassociated advantages will be better understood from the followingdescription when considered in connection with the accompanying figures.Each of the figures is provided for the purpose of illustration anddescription, and not as a definition of the limits of the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

A further understanding of the nature and advantages of the presentdisclosure may be realized by reference to the following drawings. Inthe appended figures, similar components or features may have the samereference label. Further, various components of the same type may bedistinguished by following the reference label by a dash and a secondlabel that distinguishes among the similar components. If just the firstreference label is used in the specification, the description isapplicable to any one of the similar components having the same firstreference label irrespective of the second reference label.

FIG. 1 is a block diagram illustrating details of a wirelesscommunication system.

FIG. 2 is a block diagram illustrating a design of a base station and aUE configured according to one aspect of the present disclosure.

FIG. 3 illustrates an example of a wireless communications system thatsupports millimeter wave (mm W) beam selection.

FIG. 4 is a block diagram illustrating example blocks executed toimplement one aspect of the present disclosure.

FIG. 5 is a block diagram illustrating a wireless network with a UEconfigured according to one aspect of the present disclosure.

FIG. 6 is a block diagram illustrating a wireless network with a UEconfigured according to one aspect of the present disclosure.

FIG. 7 is a block diagram illustrating an example UE configuredaccording to aspects of the present disclosure.

DETAILED DESCRIPTION

The detailed description set forth below, in connection with theappended drawings, is intended as a description of variousconfigurations and is not intended to limit the scope of the disclosure.Rather, the detailed description includes specific details for thepurpose of providing a thorough understanding of the inventive subjectmatter. It will be apparent to those skilled in the art that thesespecific details are not required in every case and that, in someinstances, well-known structures and components are shown in blockdiagram form for clarity of presentation.

Some wireless communication systems may support beamformed transmissionsbetween a base station and a user equipment (UE). For example, somesystems may operate in millimeter wave (mm W) frequency ranges, e.g., 28GHz, 40 GHz, 60 GHz, etc. Wireless communication at these frequenciesmay be associated with signal attenuation (e.g., path loss) at a higherrate than wireless communications at lower frequency ranges, e.g., 7125MHz or lower, which may be influenced by various factors, such astemperature, barometric pressure, diffraction, etc. As a result, signalprocessing techniques, such as beamforming, may be used to coherentlycombine energy and overcome path losses at these frequencies. A wirelessdevice may use a number of antenna ports (e.g., 2, 4, 8 antenna ports)associated with arrays of antennas to form beams oriented in variousdirections using a number of analog weight factors. For example, as abase station transmits downlink signals using directional beams, a UEmay also utilize beamforming for the UE's own directional receive beams(and its uplink transmit beams for uplink transmissions to the basestation).

A base station may transmit synchronization signal (SS) blocks, channelstate information—reference signal (CSI-RS) or other downlink beamsignals using downlink transmit beams each oriented in differentdirections. An SS block may be a combination of Primary SynchronizationSignals (PSS), Secondary Synchronization Signals (SSS) and/or PrimaryBroadcast Channel Signals (PBCH). The PBCH may have DemodulationReference Signals (DMRS) embedded in them. The transmit beams may, overtime, cover the geographic coverage area of a cell allowing a UE insidethe cell to synchronize with the downlink transmit beams.

A UE, in a cell with which the UE is currently communicating (a “servingcell”), may perform a beam training operation to determinesynchronization signals associated with different downlink beams thatcan be received and decoded. The UE may consider these beams ascandidates for a beam list that will be used for beam tracking purposes.The list may also contain a receive beam for receiving the downlinkbeams forming a beam pair. It can be appreciated that a UE may want abeam list with multiple beam pairs to track in case of a blocking eventthat would render one or more beam pairs unusable. It can also beappreciated that tracking multiple beams increases complexity, powerusage, and modem complexity. Accordingly, it may be important to limitor proactively manage the number of beams on the beam list. The beamlist may vary and result in different operating characteristics.

Moreover, beam training also increases complexity, power usage and modecomplexity. Accordingly it may make sense to limit beam training events.In one aspect, a UE in a serving cell may limit beam training bylimiting beam searches and performing a beam search only when the numberof useful beams in the beam list falls below a threshold, The thresholdmay be determined by the UE and/or the base station based on a varietyof factors.

In some aspects, the UE may put beams from multiple base station on itsbeam list providing rate and spatial diversity. In some aspects, servingcell beams on the beam list may be limited to a small number (e.g., 1 to3 beams). These beams might be chosen, for example, to correspond to UEbeams in different subarrays indicating correspondence to other clustersin the channel. In some aspects, the beam list may be generated based onLIE distance to the base station transmitting the beam. The UE might,for example, favor beams that are a short distance to the base stationwith the number of beams from each base station being an inversefunction of the distance. Various techniques, such as triangulation, maybe used to estimate distances.

Beam lists may also be populated or refined using other criteria. Forexample, a UE may favor beams that allow for detection and reasonabledemodulation performance with pseudo-omnidirectional (PO) beams allowingthe UE to save power. In some aspects, UEs may also request that a basestation use a coarser codebook reducing the UE power requirements andAdjacent Channel Leakage Ratio (ACLR) levels.

Aspects of the disclosure are initially described in the context of awireless communications system. Examples are also provided whichdescribe various transmit and receive beam configurations for whichefficient transmit power control may be applied using one or more RACHbeam transmission counters. Aspects of the disclosure are furtherillustrated by and described with reference to apparatus diagrams,system diagrams, and flowcharts that relate to uplink transmit powercontrol during random access procedures.

FIG. 1 illustrates an example of a wireless communications system 100 inaccordance with various aspects of the present disclosure. The wirelesscommunications system 100 includes base stations 105, UEs 115, and acore network 130. In some examples, the wireless communications system100 may be a Long Term Evolution (LTE), UM-Advanced (LTE-A) network, ora New Radio (NR) network. In some cases, wireless communications system100 may support enhanced broadband communications, ultra-reliable (i.e.,mission critical) communications, low-latency communications, andcommunications with low-cost and low-complexity devices. Wirelesscommunications system 100 may support the use of beam trainingprocedures allowing UEs 115 to determine base station 105 beams that maybe paired with one or more UE beams. UEs 115 may select some of thesebeam pairs for inclusion on a beam list.

Base stations 105 may wirelessly communicate with UEs 115 via one ormore base station antennas. Each base station 105 may providecommunication coverage for a respective geographic coverage area 110.Communication links 125 shown in wireless communications system 100 mayinclude uplink transmissions from a UE 115 to a base station 105, ordownlink transmissions, from a base station 105 to a UE 115. Controlinformation and data may be multiplexed on an uplink channel or downlinkchannel according to various techniques. Control information and datamay be multiplexed on a downlink channel, for example, using timedivision multiplexing (TDM) techniques, frequency division multiplexing(FDM) techniques, or hybrid TDM-FDM techniques. In some examples, thecontrol information transmitted during a transmission time interval(TTI) of a downlink channel may be distributed between different controlregions in a determined sequence or pattern (e.g., between a commoncontrol region and one or more UE-specific control regions).

UEs 115 may be dispersed throughout the wireless communications system100, and each UE 115 may be stationary or mobile. A UE 115 may also bereferred to as a mobile station, a subscriber station, a mobile unit, asubscriber unit, a wireless unit, a remote unit, a mobile device, awireless device, a wireless communications device, a remote device, amobile subscriber station, an access terminal, a mobile terminal, awireless terminal, a remote terminal, a handset, a user agent, a mobileclient, a client, or some other suitable terminology. A UE 115 may alsobe a cellular phone, a personal digital assistant (PDA), a wirelessmodem, a wireless communication device, a handheld device, a tabletcomputer, a laptop computer, a cordless phone, a personal electronicdevice, a handheld device, a personal computer, a wireless local loop(WLL) station, an Internet of Things (IoT) device, an Internet ofEverything (IoE) device, a machine type communication (MTC) device, anappliance, an automobile, or the like.

In some cases, a UE 115 may also be able to communicate directly withother UEs (e.g., using a peer-to-peer (P2P) or device-to-device (D2D)protocol). One or more of a group of UEs 115 utilizing D2Dcommunications may be within the coverage area 110 of a cell. Other UEs115 in such a group may be outside the coverage area 110 of a cell, orotherwise unable to receive transmissions from a base station 105. Insome cases, groups of UEs 115 communicating via D2D communications mayutilize a one-to-many (1:M) system in which each UE 115 transmits toevery other UE 115 in the group. In some cases, a base station 105facilitates the scheduling of resources for D2D communications. In othercases, D2D communications are carried out independent of a base station105.

Some UEs 115, such as MTC or IoT devices, may be low cost or lowcomplexity devices, and may provide for automated communication betweenmachines, i.e., Machine-to-Machine (M2M) communication, M2M or MTC mayrefer to data communication technologies that allow devices tocommunicate with one another or a base station without humanintervention. For example, M2M or MTC may refer to communications fromdevices that integrate sensors or meters to measure or captureinformation and relay that information to a central server orapplication program that can make use of the information or present theinformation to humans interacting with the program or application. SomeUEs 115 may be designed to collect information or enable automatedbehavior of machines. Examples of applications for MTC devices includesmart metering, inventory monitoring, water level monitoring, equipmentmonitoring, healthcare monitoring, wildlife monitoring, weather andgeological event monitoring, fleet management and tracking, remotesecurity sensing, physical access control, and transaction-basedbusiness charging.

In some cases, an MTC device may operate using half-duplex (one-way)communications at a reduced peak rate. MTC devices may also heconfigured to enter a power saving “deep sleep” mode when not engagingin active communications. In some cases, MTC or IoT devices may bedesigned to support mission critical functions and wirelesscommunications system may be configured to provide ultra-reliablecommunications for these functions.

Base stations 105 may communicate with the core network 130 and with oneanother. For example, base stations 105 may interface with the corenetwork 130 through backhaul links 132 (e.g., S1, etc.). Base stations105 may communicate with one another over backhaul links 134 (e.g., X2,etc.) either directly or indirectly (e.g., through core network 130).Base stations 105 may perform radio configuration and scheduling forcommunication with UEs 115, or may operate under the control of a basestation controller (not shown). In some examples, base stations 105 maybe macro cells, small cells, hot spots, or the like.

A base station 105 may be connected by an S1 interface to the corenetwork 130. The core network may be an evolved packet core (EPC), whichmay include at least one mobility management entity (MME), at least oneserving gateway (S-GW), and at least one Packet Data Network (PDN)gateway (P-GW), The MME may be the control node that processes thesignaling between the UE 115 and the EPC. All user Internet Protocol(IP) packets may be transferred through the S-GW, which itself may beconnected to the P-GW. The P-GW may provide IP address allocation aswell as other functions. The P-GW may be connected to the networkoperators IP services. The operators IP services may include theInternet, the Intranet, an IP Multimedia Subsystem (IMS), and aPacket-Switched (PS) Streaming Service.

The core network 130 may provide user authentication, accessauthorization, tracking, Internet Protocol (IP) connectivity, and otheraccess, routing, or mobility functions. At least some of the networkdevices, such as base station 105 may include subcomponents such as anaccess network entity, which may be an example of an access nodecontroller (ANC). Each access network entity may communicate with anumber of UEs 115 through a number of other access network transmissionentities, each of which may be an example of a smart radio head, or atransmission/reception point (TRP). In some configurations, variousfunctions of each access network entity or base station 105 may bedistributed across various network devices (e.g., radio heads and accessnetwork controllers) or consolidated into a single network device (e.g.,a base station 105).

Wireless communications system 100 may operate in an ultra-highfrequency (UHF) frequency region using frequency bands from 700 MHz to2600 MHz (2.6 GHz), although some networks (e.g., a wireless local areanetwork (WLAN)) may use frequencies as high as 5 GHz. This region mayalso be known as the decimeter band, since the wavelengths range fromapproximately one decimeter to one meter in length. UHF waves maypropagate mainly by line of sight, and may be blocked by buildings andenvironmental features. However, the waves may penetrate wallssufficiently to provide service to UEs 115 located indoors. Transmissionof UHF waves is characterized by smaller antennas and shorter range(e.g., less than 100 km) compared to transmission using the smallerfrequencies (and longer waves) of the high frequency (HF) or very highfrequency (VHF) portion of the spectrum. In some cases, wirelesscommunications system 100 may also utilize extremely high frequency(EHF) portions of the spectrum (e.g., from 30 GHz to 300 GHz). Thisregion may also be known as the millimeter band, since the wavelengthsrange from approximately one millimeter to one centimeter in length.Thus, EHF antennas may be even smaller and more closely spaced than UHFantennas. In some cases, this may facilitate use of antenna arrayswithin a UE 115 (e.g., for directional beamforming). However, EHFtransmissions may be subject to even greater atmospheric attenuation andshorter range than UHF transmissions.

Wireless communications system 100 may support mm W communicationsbetween UEs 115 and base stations 105. Devices operating in mm W or EHFbands may have multiple antennas to allow beamforming. That is, a basestation 105 may use multiple antennas or antenna arrays to conductbeamforming operations for directional communications with a UE 115.Beamforming (Which may also be referred to as spatial filtering ordirectional transmission) is a signal processing technique that may beused at a transmitter (e.g., a base station 105) to shape and/or steeran antenna beam in the direction of a target receiver (e.g., a UE 115).This may be achieved by configuring circuitry associated with elementsof an antenna array to combine the signals transmitted by the elementsin such a way that transmitted signals at particular angles relative tothe antennas experience constructive interference while othersexperience destructive interference.

Multiple-input multiple-output (MIMO) wireless systems use atransmission scheme between a transmitter (e.g., a base station 105) anda receiver (e.g., a UE 115), where both transmitter and receiver areequipped with multiple antennas. Some portions of wirelesscommunications system 100 may use beamforming. For example, base station105 may have an antenna array with a number of rows and columns ofantenna ports that the base station 105 may use for beamforming in itscommunication with UE 115. Signals may be transmitted multiple times indifferent directions (e.g., each transmission may be beamformeddifferently). A mm W receiver (e.g., a LTE 115) may try multiple beams(e.g., antenna subarrays) While receiving the synchronization signals.

In some cases, the antennas of a base station 105 or UE 115 may belocated within one or more antenna arrays, which may support beamformingor MIMO operation. One or more base station antennas or antenna arraysmay be collocated at an antenna assembly, such as an antenna tower. Insome cases, antennas or antenna arrays associated with a base station105 may be located in diverse geographic locations. A base station 105may multiple use antennas or antenna arrays to conduct beamformingoperations for directional communications with a UE 115.

In some cases, wireless communications system 100 may be a packet-basednetwork that operates according to a layered protocol stack. In the userplane, communications at the bearer or Packet Data Convergence Protocol(PDCP) layer may be IP-based. A radio link control (RLC) layer may insome cases perform packet segmentation and reassembly to communicateover logical channels. A medium access control (MAC) layer may performpriority handling and multiplexing of logical channels into transportchannels. The MAC layer may also use hybrid automatic repeat request(HARQ) to provide retransmission at the MAC layer to improve linkefficiency. In the control plane, the radio resource control (RRC)protocol layer may provide establishment, configuration, and maintenanceof an RRC connection between a UE 115 and a network device or corenetwork 130 supporting radio bearers for user plane data. At thephysical (PHY) layer, transport channels may be mapped to physicalchannels.

Wireless communications system 100 may support operation on multiplecells or carriers, a feature which may be referred to as carrieraggregation (CA) or multi-carrier operation. A carrier may also bereferred to as a component carrier (CC), a layer, a channel, etc. Theterms “carrier,” “component carrier,” “cell,” and “channel” may be usedinterchangeably herein. A UE 115 may be configured with multipledownlink CCs and one or more uplink CCs for carrier aggregation. Carrieraggregation may be used with both FDD and TDD component carriers.

In some cases, wireless communications system 100 may utilize enhancedcomponent carriers (eCCs). An eCC may be characterized by one or morefeatures including: wider bandwidth, shorter symbol duration, shorterTTIs, and modified control channel configuration. In some cases, an eCCmay be associated with a carrier aggregation configuration or a dualconnectivity configuration (e.g., when multiple serving cells have asuboptimal or non-ideal backhaul link). An eCC may also be configuredfor use in unlicensed spectrum or shared spectrum (where more than oneoperator is allowed to use the spectrum). An eCC characterized by widebandwidth may include one or more segments that may be utilized by UEs115 that are not capable of monitoring the whole bandwidth or prefer touse a limited bandwidth (e.g., to conserve power).

In some cases, an eCC may utilize a different symbol duration than otherCCs, which may include use of a reduced symbol duration as compared withsymbol durations of the other CCs. A shorter symbol duration isassociated with increased subcarrier spacing. A device, such as a UP 115or base station 105, utilizing eCCs may transmit wideband signals (e.g.,20, 40, 60, 80 MHz, etc.) at reduced symbol durations (e.g., 16.67microseconds). A TTI in eCC may consist of one or multiple symbols. Insome cases, the TTI duration (that is, the number of symbols in a TTI)may be variable.

A shared radio frequency spectrum band may be utilized in an NR sharedspectrum system. For example, an NR shared spectrum may utilize anycombination of licensed, shared, and unlicensed spectrums, among others.The flexibility of eCC symbol duration and subcarrier spacing may allowfor the use of eCC across multiple spectrums. In some examples, NRshared spectrum may increase spectrum utilization and spectralefficiency, specifically through dynamic vertical (e.g., acrossfrequency) and horizontal (e.g., across time) sharing of resources.

In some cases, wireless communications system 100 may utilize bothlicensed and unlicensed radio frequency spectrum bands. For example,wireless communications system 100 may employ LTE License AssistedAccess (LTE-LAA) or LTE Unlicensed (LTE U) radio access technology or NRtechnology in an unlicensed band such as the 5 Ghz Industrial,Scientific, and Medical (ISM) band. When operating in unlicensed radiofrequency spectrum bands, wireless devices such as base stations 105 andUEs 115 may employ listen-before-talk (LBT) procedures to ensure thechannel is clear before transmitting data. In some cases, operations inunlicensed bands may be based on a CA configuration in conjunction withCCs operating in a licensed band. Operations in unlicensed spectrum mayinclude downlink transmissions, uplink transmissions, or both. Duplexingin unlicensed spectrum may be based on frequency division duplexing(FDD), time division duplexing (TDD) or a combination of both.

A UE 115 attempting to access a wireless network may perform an initialcell search by detecting a primary synchronization signal (PSS) from abase station 105. The PSS may enable synchronization of slot timing andmay indicate a physical layer identity value. The UE 115 may thenreceive a secondary synchronization signal (SSS). The SSS may enableradio frame synchronization, and may provide a cell identity value,which may be combined with the physical layer identity value to identifythe cell. The SSS may also enable detection of a duplexing mode and acyclic prefix length. After receiving the PSS and SSS, the UP 115 mayreceive a master information block (MIB), which may be transmitted in aphysical broadcast channel (PBCH) by the base station 105. The MIB maycontain system bandwidth information, a system frame number (SFN), and aphysical HARQ indicator channel (PHICH) configuration.

After decoding the MIB, the UE 115 may receive one or more systeminformation blocks (SIBs). For example, SIB1 may contain cell accessparameters and scheduling information for other SIBs. For instance, SIB1access information, including cell identity information, and it mayindicate whether a UE 115 is allowed to camp on a coverage area 110.SIB1 also includes cell selection information (or cell selectionparameters) and scheduling information for other SIBs, such as SIB2.Decoding SIB1 may enable the UE 115 to receive SIB2, where SIB2 maycontain radio resource control (RRC) configuration information relatedto random access channel (RACH) procedures, paging, physical uplinkcontrol channel (PUCCH), physical uplink shared channel (PUSCH), powercontrol, sounding reference signal (SRS), and cell barring. DifferentSIBs may be defined according to the type of system informationconveyed. In some cases, SIB2 may be scheduled dynamically according toinformation in SIB1, and includes access information and parametersrelated to common and shared channels.

After the UE 115 decodes SIB2, it may transmit a RACH preamble to a basestation 105. For example, the RACH preamble may be randomly selectedfrom a set of 64 predetermined sequences. This may enable the basestation 105 to distinguish between multiple UEs 115 trying to access thesystem simultaneously. The base station 105 may respond with a randomaccess response that provides an uplink resource grant, a timingadvance, and a temporary cell radio network temporary identifier(C-RNTI). The UE 115 may then transmit an RRC connection request alongwith a temporary mobile subscriber identity (TMSI) (e.g., if the UE 115has previously been connected to the same wireless network) or a randomidentifier. The RRC connection request may also indicate the reason theUE 115 is connecting to the network (e.g., emergency, signaling, dataexchange, etc.). The base station 105 may respond to the connectionrequest with a contention resolution message addressed to the UE 115,which may provide a new C-RNTI. If the UE 115 receives a contentionresolution message with the correct identification, it may proceed withRRC setup. If the UE 115 does not receive a contention resolutionmessage (e.g., if there is a conflict with another UE 115), the UE 115may repeat the RACH process by transmitting a new RACH preamble.

Wireless devices in wireless communications system 100 may sendtransmissions in accordance with a certain link budget. The link budgetmay account for allowed signal attenuation between a UE 115 and a basestation 105, as well as antenna gains at the UE 115 and base station105. Accordingly, the link budget may provide, for example, a maximumtransmit power for the various wireless devices within wirelesscommunications system 100. In some cases, a UE 115 may coordinatetransmit power with a serving base station 105 to mitigate interference,improve the uplink data rate, and prolong battery life.

Uplink power control may include a combination of open-loop andclosed-loop mechanisms. In open-loop power control, the UE transmitpower may depend on estimates of the downlink path-loss and channelconfiguration. In closed-loop power control, the network may directlycontrol the UE transmit power using explicit power-control commands.Open-loop power control may he used for initial access, such as thetransmission of a physical random access channel (PRACH) by a UE 115,whereas both open and closed loop control may be used for uplink controland data transmission. A UE 115 may determine power using an algorithmthat takes into account a maximum transmission power limit, a targetbase station receive power, path loss, modulation and coding scheme(MCS), the number of resources used for transmission, and a format ofthe transmitted data (e.g., physical uplink control channel (PUCCH)format). Power adjustments may be made by a base station 105 using atransmit power command (TPC) messages, which may incrementally adjustthe transmit power of a UE 115 as appropriate.

FIG. 2 shows a block diagram of a base station 105 and a UE 115, whichmay be one of the base stations 105 and one of the UEs 115 in FIG. 1. Atthe base station 105, a transmit processor 220 may receive data from adata source 212 and control information from a controller/processor 240.The control information may be for the PBCH, PCFICH, PHICH, PDCCH,EPDCCH, MPDCCH etc. The data may be for the PDSCH, etc. The transmitprocessor 220 may process (e.g., encode and symbol map) the data andcontrol information to obtain data symbols and control symbols,respectively. The transmit processor 220 may also generate referencesymbols, e.g., for the PSS, SSS, and cell-specific reference signal. Atransmit (TX) multiple-input multiple-output (MIMO) processor 230 mayperform spatial processing (e.g., precoding) on the data symbols, thecontrol symbols, and/or the reference symbols, if applicable, and mayprovide output symbol streams to the modulators (MODS) 232 a through 232t. Each modulator 232 may process a respective output symbol stream(e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator232 may further process (e.g., convert to analog, amplify, filter, andupconvert) the output sample stream to obtain a downlink signal.Downlink signals from modulators 232 a through 232 t may be transmittedvia the antennas 234 a through 234 t, respectively.

At the UE 115, the antennas 252 a through 252 r may receive the downlinksignals from the base station 105 and may provide received signals tothe demodulators (DEMODs) 254 a through 254 r, respectively. Eachdemodulator 254 may condition (e.g., filter, amplify, downconvert, anddigitize) a respective received signal to obtain input samples. Eachdemodulator 254 may further process the input samples (e.g., for OFDM,etc.) to obtain received symbols. A MIMO detector 256 may obtainreceived symbols from all the demodulators 254 a through 254 r, performMIMO detection on the received symbols if applicable, and providedetected symbols. A receive processor 258 may process (e.g., demodulate,deinterleave, and decode) the detected symbols, provide decoded data forthe UE 115 to a data sink 260, and provide decoded control informationto a controller/processor 280.

On the uplink, at the UE 115, a transmit processor 264 may receive andprocess data (e.g., for the PUSCH from a data source 262 and controlinformation (e.g., for the PUCCH) from the controller/processor 280. Thetransmit processor 264 may also generate reference symbols for areference signal. The symbols from the transmit processor 264 may beprecoded by a TX MIMO processor 266 if applicable, further processed bythe modulators 254 a through 254 r (e.g., for SC-FDM, etc.), andtransmitted to the base station 105. At the base station 105, the uplinksignals from the UE 115 may be received by the antennas 234, processedby the demodulators 232, detected by a MIMO detector 236 if applicable,and further processed by a receive processor 238 to obtain decoded dataand control information sent by the UE 115. The processor 238 mayprovide the decoded data to a data sink 239 and the decoded controlinformation to the controller/processor 240.

The controllers/processors 240 and 280 may direct the operation at thebase station 105 and the UE 115, respectively. The controller/processor240 and/or other processors and modules at the base station 105 mayperform or direct the execution of various processes for the techniquesdescribed herein. The controllers/processor 280 and/or other processorsand modules at the UE 115 may also perform or direct the execution ofthe functional blocks illustrated in FIG. 4, and/or other processes forthe techniques described herein. The memories 242 and 282 may store dataand program codes for the base station 105 and the UE 115, respectively.A scheduler 244 may schedule UEs for data transmission on the downlinkand/or uplink.

FIG. 3 illustrates an example of a wireless communications system 300that supports mm W beam management. In some examples, wirelesscommunications system 300 may implement aspects of wirelesscommunications system 100. For example, wireless communications system300 may include a base station 105 a and a UE 115 a within coverage area310 a of base station 105 a, which may be examples of the correspondingdevices described with reference to FIGS. 1 and 2. When configuredaccording to 3GPP Release 15, UE 115 a may report channel stateinformation (CSI) using different modes including channel qualityindicator (CQI), preceding matrix indicator (PMI), CSI reference signal(CSI-RS) resource indicator (CRI), synchronization signal block resourceindicator (SSBRI), layer indicator (LI), rank indicator (RI), layer 1RSSP (L1-RSRP). Among these, base station 105 a may use L1-RSRP as themetric for selecting the best beam(s) for communications. Wirelesscommunications system 300 may support beam management based on a rankingof available beams according to L1-RSRP.

Beam management according to the described example provides for basestation 105 a to configure UE 115 a with N CSI resources and prompts UE115 a to report the best K beams and their corresponding L1-RSRP. In oneexample of operation, base station 105 a configures UE 115 a to reportthe best two beams. UE 115 a measures the L1-RSRP of a reference signal(e.g., SSB, CSI-RS, etc.) on each of beams 305 a-d, Using the L1-RSRPmeasurements, UE 115 a identities beams 305 a and 305 b as the two beamshaving the highest L1-RSRP value. UE 115 a then reports the subset ofbeams, beams 305 a and 305 b, along with the L1-RSRP measurements ofbeams 305 a and 305 b. Base station 105 a receives the report andselects the beam or beams for further downlink transmissions. One issuewith using L1-RSRP measurements to select beams is that the beam thatyields the best L1-RSRP may not be the best choice in terms of signal tointerference plus noise (SINR). Thus, high L1-RSRP beams, such as beams305 a and 305 b may also experience a high degree of interference andnoise (e.g., interference from UEs 115 b and 115 c). UE 115 a may wantto choose a beam which suffers less interference, even if it means notchoosing the beam having the best L1-RSRP. Various aspects of thepresent disclosure relate to the addition of a L1-SINR CSI reportingnode that is considered for beam. management. The L1-SINR may also becomputed based on SSB or other reference signal, such as CSI-RS.

FIG. 4 is a block diagram illustrating example blocks executed by a UEto implement one aspect of the present disclosure. The example blockswill also be described with respect to UE 115 as illustrated in FIG. 7.FIG. 7 is a block diagram illustrating UE 115 configured according toone aspect of the present disclosure. UE 115 includes the structure,hardware, and components as illustrated for UE 115 of FIG. 2. Forexample, UE 115 includes controller/processor 280, which operates toexecute logic or computer instructions stored in memory 282, as well ascontrolling the components of UE 115 that provide the features andfunctionality of UE 115. UE 115, under control of controller/processor280, transmits and receives signals via radios 700 a-r and antennas 252a-r. Radios 700 a-r includes various components and hardware, asillustrated in FIG. 2 for UE 115, including modulator/demodulators 254a-r, MIMO detector 256, receive processor 258, transmit processor 264,and TX MIMO processor 266.

At block 400, the UE receives a CSI reporting configuration message froma serving base station, wherein the CSI reporting configuration messageidentifies a set of CSI resources for reporting CSI on a plurality ofbeams by the UE. A UE, such as UE 115, receives the CSI reportingconfiguration message from a serving base station via antennas 252 a-rand wireless radios 700 a-r. The reporting configuration information isstored in memory 282 in CSI reporting configuration 701. The reportingconfiguration identifies to UE 115 the type of beam management reportingmode that will be used by UE 115 in ranking and reporting the bestavailable beams.

At block 401, the UE 115 measures an interference plus noise metric of afirst signaling resource on each beam of the plurality of beams. Inresponse to the configuration information received, UE 115, undercontrol of controller/processor 280, executes measurement logic 701,stored in memory 282. The execution of measurement logic 701 providesthe functionality for UE 115, under control of controller/processor 280to measure the interference plus noise metric of the identifiedsignaling resource (e.g., CSI-RS, SSB, etc.) in each of the beamsavailable for communication.

At block 402, the UE measures a power contribution metric of a secondsignaling resource of each beam of the plurality of beams. The powercontribution metric represents the average power of resource elementsused to carry a reference signal. With the execution of measurementlogic 702, UE 115 measures the power contribution on the secondsignaling resources to derive the power contribution metric. In variousalternative example implementations, the second signaling resources maybe the same resources UE 115 uses to measure the interference plus noisemetric, or may be different resources, or different instances of thesame signaling resources.

At block 403, the UE ranks the plurality of beams based on a rankingparameter, wherein the ranking parameter includes one of: theinterference plus noise metric, or the power contribution metric, andselects a subset of highest ranked beams from the ranked plurality ofbeams. The beam management reporting mode identified in theconfiguration message, stored at CSI reporting configuration 701,prompts UE 115 to execute, under control of controller/processor 280,beam ranking logic 703, in memory 282. The execution of beam rankinglogic 703 provides the functionality for UE 115 to rank the availablebeams. Beam ranking logic 703 may provide for ranking the beamsaccording to the interference plus noise metric, according to the powercontribution metric, or some combination of both. For example, the typeof beam management reporting mode may provide for the beams to be rankedaccording to either the power contribution metric or the interferenceplus noise metric, while such beams are designated for reporting as oneof the K best ranked beams provided that the other parameter (e.g.,interference plus noise, where the ranking is performed based on powercontribution, or power contribution, where the ranking is performedbased on interference plus noise) meets a predetermined threshold level.

At block 404, the UE transmits identification of the subset of highestranked beams to the serving base station via the set of CSI resources.As UE 115 identifies the highest ranked beams considered at least inpart based on the interference plus noise metric associated with thebeams, it executes, under control of controller/processor 280, reportgenerator logic 704. The execution of report generator logic 704provides the functionality for UE 115 to generate the reporting messagethat includes identification of the subset of highest ranked beamsaccording to the beam management reporting mode, in addition to anymeasurements or metrics of the power contribution metric and/orinterference plus noise metric.

FIG. 5 is a block diagram illustrating a wireless network 500 with UE115 a configured according to one aspect of the present disclosure. UE115 a is located with coverages areas 510 a and 510 b served by basestations 105 a and 105 b, respectively, and where the number of beams toreport, K, is two. UE 115 a receives configuration message from basestation 105 a that identifies a set of CSI resources along with anindication to report back the two best beams. According to aspects ofthe present disclosure, the configuration message may also include a CSIreporting mode for interference plus noise measurements to use in beammanagement.

In a first example aspect illustrated in FIG. 5, the interference phisnoise reporting mode is separate from the power contribution reportingmode. Accordingly, UE 115 a measures a signaling resource (e.g., CSI-RS,SSB) within each of beams 505 a-d and beams 506 a-d both for a powercontribution (e.g., L1-RSRP) and for interference plus noise (e.g.,L1-SINR). UE 115 a determines that the two highest power contribution(e.g., L1-RSRP) measurements are from beams 505 b and 506 a, anddetermines that the two highest interference plus noise measurements arefrom beams 505 c and 505 a. According to the first example aspect, UE115 a reports to base station 105 a an identification of beams 505 b and506 a along with the corresponding measured power contribution fromthose beams. UE 115 a also reports to base station 105 a identificationof beams 505 c and 505 a along with the corresponding measuredinterference plus noise metric. Base station 105 a may then determinewhich of the beams to use for further downlink transmissions to UE 115.When beams from a neighboring base station, such as base station 105 b,generate some of the top K beams, base station 105 a may use thosemeasurements to trigger a handover to base station 105 b or may signaldata for joint transmission or other coordinated transmissions (e.g.,coordinated multipoint (CoMP) transmissions, carrier aggregation, or thelike) to base station 105 b.

According to a second example aspect illustrated in FIG. 5, theinterference plus noise reporting mode includes conditional reportingbased on supplemental measurements compared against a predeterminedthreshold value. For example, UE 115 a measures both power contributionand interference plus noise on the signalling resources of each beam. Ina first optional implementation, UE 115 a sorts or ranks the top K beamsaccording to power contribution. However, the beams with the highestpower contribution metrics are not identified by UP 115 a as one of thesubset of highest ranked beams unless the interference plus noise metricfor each such beam also exceeds a predetermined threshold. Thus, if beam506 a measures the highest value of power contribution out of all ofbeams 505 a-d and 506 a-d but has an interference plus noise metric thatdoes not meet the predetermined threshold, UE 115 a will not includebeam 506 a in the subset of highest-ranked beams reported to basestation 105 a.

In a second optional implementation, the opposite measurements are used,such that UE 115 a sorts or ranks the top K beams according to theirinterference plus noise metric. UE 115 a will only designate those beamshaving the highest interference plus noise metric for the subset ofhighest ranked beams to report if the power contribution metric of thedesignated beams also meets a predetermined power threshold.

It should be noted that the power contribution metric or interferenceplus noise metric compared to the threshold value may either be theactual measurement of the signalling resource or it may be a relationalmeasurement. For example, when ranking according to power contribution,UE 115 a ranks the beams from highest to lowest power contribution: beam506 a, 505 a, 506 b, 505 b, 505 c, 506 c, 505 d, 506 d, while, fromhighest to lowest, the interference plus noise metrics are beam 506 b,505 b, 505 c, 506 c, 506 a, 505 a, 505 d, 506 d. The top two beams areinitially identified as beams 506 a and beam 505 a. However, in a firstoptional example, the interference plus noise metric of beam 506 a fallsbelow the predetermined threshold, thus, it is not included. In a secondoptional example, which uses a relational measurement, UE 115 a wouldfind the difference in interference plus noise metrics between beam 506a and the highest value of interference plus noise metric (beam 506 b)and compare that value to a predetermined threshold. If the differencein interference plus noise metric between beams 506 a and 506 b is notsignificant, then it may meet the threshold, thus, UE 115 a may includeidentification of beam 506 a as one of the K highest ranked beams in itsreport to base station 105 a.

In a third optional implementation, the CSI configuration message mayindicate which measurement to use as the ranking parameter. Base station105 a may indicate for UE 115 a to rank the beams according to the powercontribution metric or the interference plus noise metric. Thus, withreference to the rankings identified above, where base station 105 aconfigures UE 115 a to rank according to power contribution metric, UE115 a would report identification of beams 506 a and 505 a, while, wherebase station 105 a configures UE 115 a to rank according to interferenceplus noise metric, UE 115 a would report identification of beams 506 band 505 b. With either ranking parameter, UE 115 a would also send boththe power contribution metric and interference plus power metric for thereported two beams. Base station 105 a may then consider both powercontribution and interference when determining the beam or beams toselect for transmissions to UE 115 a.

As noted above, SINR measurements are not defined for use in beammanagement of mm W operations in 3GPP Rel-15. Thus, according to theRel-15 standards, the E-UTRA reference signal-signal to noise andinterference ratio (E-UTRA RS-SINR) is defined as the linear averageover the power contribution of the resource elements carryingcell-specific reference signals divided by the linear average of thenoise and interference power contribution over the resource elementscarrying cell-specific reference signals within the same frequencybandwidth. When used for beam management, according to the variousaspects of the present disclosure, the definition for L1-SINRmeasurement may be modified.

In a first optional aspect, UE 115 a may measure the power contributionon the given signalling resource (e.g., CSI-RS or SSB), but may averagethe interference plus noise metric over multiple instances of thesignalling resources within the same transmission configurationindicator (TCI) state for the interference plus noise computation. Theaveraging over the multiple instances provides a combined look at theinterference that arises over period of the TCI state.

In a second optional aspect, UE 115 a may measure the power contributionon the given signalling resource, but will select either the maximum orminimum interference plus noise measurement over the multiple instancesof the signalling resources within the same TO state for theinterference plus noise computation. In a third optional aspect, UE 115a may measure the power contribution and the interference plus noisemetric over the same signalling resource.

FIG. 6 is a block diagram illustrating wireless communication network600 with UE 115 a configured according to one aspect of the presentdisclosure. As illustrated in FIG. 6, UE 115 a is configured withmultiple receiver chains 601 a and 601 b operable in combination forreceiver diversity. Each of receiver chain 601 a and 601 b includes anantenna and a set of signal processing components for processing thesignals received via the antenna and may provide diversity branches forsignals received from base station 105 a, Under the Rel-15 definition ofinterference plus noise measurement, when receiver diversity is in useby a UE, such as UE 115 a, the reported value shall not be lower thanthe corresponding E-UTRA RS-SINR of any of the individual diversitybranches of receiver chains 601 a and 601 b.

According to the illustrated aspect of FIG. 6, the definition may bemodified in consideration of the interference plus noise metric beingconsidered for beam management. In a first optional aspect, UE 115 acalculates the interference plus noise metric as the average of the SINRof the individual diversity branches, receiver chains 601 a and 601 b.In a second optional aspect, UE 115 a. would calculate the interferenceplus noise metric as the minimum or maximum of the SINR of theindividual diversity branches, receiver chains 601 a and 601 b.Selection of the minimum of the SINR measurements would be equivalent tothe defined limitations discussed with respect to the Rel-15 definition.In a third optional aspect, UE 115 a would determine an effectiveinterference plus noise metric, calculated as the SINR corresponding tothe sum-capacity over individual diversity branches, receiver chains 601a and 601 b.

Those of skill in the art would understand that information and signalsmay be represented using any of a variety of different technologies andtechniques. For example, data, instructions, commands, information,signals, bits, symbols, and chips that may be referenced throughout theabove description may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orparticles, or any combination thereof.

The functional blocks and modules in FIG. 4 may comprise processors,electronics devices, hardware devices, electronics components, logicalcircuits, memories, software codes, firmware codes, etc., or anycombination thereof.

Those of skill would further appreciate that the various illustrativelogical blocks, modules, circuits, and algorithm steps described inconnection with the disclosure herein may be implemented as electronichardware, computer software, or combinations of both. To clearlyillustrate this interchangeability of hardware and software, variousillustrative components, blocks, modules, circuits, and steps have beendescribed above generally in terms of their functionality. Whether suchfunctionality is implemented as hardware or software depends upon theparticular application and design constraints imposed on the overallsystem. Skilled artisans may implement the described functionality invarying ways for each particular application, but such implementationdecisions should not be interpreted as causing a departure from thescope of the present disclosure. Skilled artisans will also readilyrecognize that the order or combination of components, methods, orinteractions that are described herein are merely examples and that thecomponents, methods, or interactions of the various aspects of thepresent disclosure may be combined or performed in ways other than thoseillustrated and described herein.

The various illustrative logical blocks, modules, and circuits describedin connection with the disclosure herein may be implemented or performedwith a general-purpose processor, a digital signal processor (DSP), anapplication specific integrated circuit (ASIC), a field programmablegate array (FPGA) or other programmable logic device, discrete gate ortransistor logic, discrete hardware components, or any combinationthereof designed to perform the functions described herein. Ageneral-purpose processor may be a microprocessor, but in thealternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

The steps of a method or algorithm described in connection with thedisclosure herein may be embodied directly in hardware, in a softwaremodule executed by a processor, or in a combination of the two. Asoftware module may reside in RAM memory, flash memory, ROM memory,EPROM memory, EEPROM memory, registers, hard disk, a removable disk, aCD-ROM, or any other form of storage medium known in the art. Anexemplary storage medium is coupled to the processor such that theprocessor can read information from, and write information to, thestorage medium. In the alternative, the storage medium may be integralto the processor. The processor and the storage medium may reside in anASIC, The ASIC may reside in a user terminal. In the alternative, theprocessor and the storage medium may reside as discrete components in auser terminal.

In one or more exemplary designs, the functions described may beimplemented in hardware, software, firmware, or any combination thereof.If implemented in software, the functions may be stored on ortransmitted over as one or more instructions or code on acomputer-readable medium. Computer-readable media includes both computerstorage media and communication media including any medium thatfacilitates transfer of a computer program from one place to another.Computer-readable storage media may be any available media that can beaccessed by a general purpose or special purpose computer. By way ofexample, and not limitation, such computer-readable media can compriseRAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic diskstorage or other magnetic storage devices, or any other medium that canbe used to carry or store desired program code means in the form ofinstructions or data structures and that can be accessed by ageneral-purpose or special-purpose computer, or a general-purpose orspecial-purpose processor. Also, a connection may be properly termed acomputer-readable medium. For example, if the software is transmittedfrom a website, server, or other remote source using a coaxial cable,fiber optic cable, twisted pair, or digital subscriber line (DSL), thenthe coaxial cable, fiber optic cable, twisted pair, or DSL, are includedin the definition of medium. Disk and disc, as used herein, includescompact disc (CD), laser disc, optical disc, digital versatile disc(DVD), floppy disk and blu-ray disc where disks usually reproduce datamagnetically, while discs reproduce data optically with lasers.Combinations of the above should also be included within the scope ofcomputer-readable media.

As used herein, including in the claims, the term “and/or,” when used ina list of two or more items, means that any one of the listed items canbe employed by itself, or any combination of two or more of the listeditems can be employed. For example, if a composition is described ascontaining components A, B, and/or C, the composition can contain Aalone; B alone; C alone; A and B in combination; A and C in combination;B and C in combination; or A, B, and C in combination. Also, as usedherein, including in the claims, “or” as used in a list of itemsprefaced by “at least one of” indicates a disjunctive list such that,for example, a list of “at least one of A, B, or C” means A or B or C orAB or AC or BC or ABC (i.e., A and B and C) or any of these in anycombination thereof.

The previous description of the disclosure is provided to enable anyperson skilled in the art to make or use the disclosure. Variousmodifications to the disclosure will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other variations without departing from the spirit or scopeof the disclosure. Thus, the disclosure is not intended to be limited tothe examples and designs described herein but is to be accorded thewidest scope consistent with the principles and novel features disclosedherein.

What is claimed is:
 1. A method of wireless communication, comprising:receiving, at a user equipment (UE), a channel state information (CSI)reporting configuration message from a serving base station, wherein theCSI reporting configuration message identifies a set of CSI resourcesfor reporting CSI of a plurality of beams by the UE; measuring, by theUE, an interference plus noise metric of a first signaling resource ofeach beam of the plurality of beams; measuring by the UE, a powercontribution metric of a second signaling resource of the each beam ofthe plurality of beams; ranking, by the UE, the plurality of beams basedon a ranking parameter, wherein the ranking parameter includes one of:the interference plus noise metric, or the power contribution metric;selecting, by the UE, a subset of highest ranked beams from theplurality of beams according to the ranking; and transmitting, by theUE, identification of the subset of highest ranked beams to the servingbase station via the set of CSI resources.
 2. The method of claim 1,wherein the ranking includes ranking the plurality of beams based on theinterference plus noise metric.
 3. The method of claim 2, furtherincluding: selecting, by the UE, a second subset of beams from theplurality of beams based on the power contribution metric; andtransmitting, by the UE, a second identification of the second subset ofbeams to the serving base station.
 4. The method of claim 2, wherein:the selecting of the subset of highest ranked beams comprises selectingbeams from among the plurality of beams such that each of the selectedbeams has a respective power contribution metric that exceeds apredetermined power contribution threshold.
 5. The method of claim 1,wherein: the selecting of the subset of highest ranked beams comprisesselecting beams from among the ranked plurality of beams such that eachof the selected beams has a respective interference plus noise metricthat exceeds a predetermined interference plus noise threshold.
 6. Themethod of claim 1, wherein the transmitting further includes:transmitting the interference plus noise metric and the powercontribution metric for each beam of the subset of highest ranked beams.7. The method of claim 1, wherein the measuring the first signalingresource includes: measuring a plurality of instances of the firstsignaling resource within a same transmission configuration indicator(TCI) state; and one of: averaging a plurality of interference plusnoise measurements of the plurality of instances of the first signalingresource for the interference plus noise metric; or selecting a maximuminterference plus noise measurement of the plurality of instances of thefirst signaling resource for the interference plus noise metric; orselecting a minimum interference plus noise measurement of the pluralityof instances of the first signaling resource for the interference plusnoise metric.
 8. The method of claim 1, wherein the first signalingresource is a same resource as the second signaling resource.
 9. Themethod of claim 1, wherein the receiving occurs over a plurality ofreceiver diversity branches at the UE, wherein the measuring of theinterference plus noise metric includes one of: calculating an averageinterference plus noise metric of interference plus noise measurementsof each of the plurality of receiver diversity branches, wherein theaverage interference plus noise metric corresponds to the interferenceplus noise metric; identifying a minimum interference plus noise metricof the plurality of receiver diversity branches, wherein the minimuminterference plus noise metric corresponds to the interference plusnoise metric; identifying a maximum interference plus noise metric ofthe plurality of receiver diversity branches, wherein the maximuminterference plus noise metric corresponds to the interference plusnoise metric; or calculating an effective interference plus noise metricbased on a sum-capacity measurement of interference plus noise over theplurality of receiver diversity branches, wherein the effectiveinterference plus noise metric corresponds to the interference plusnoise metric.
 10. The method of claim 1, wherein the CSI reportingconfiguration message specifies a quantity of beams for the UE to reportin the subset of highest ranking beams.
 11. An apparatus configured forwireless communication, comprising: means for receiving, at a userequipment (UE), a channel state information (CSI) reportingconfiguration message from a serving base station, wherein the CSIreporting configuration message identifies a set of CSI resources forreporting CSI of a plurality of beams by the UE; means for measuring, bythe UE, an interference plus noise metric of a first signaling resourceof each beam of the plurality of beams; means for measuring by the UE, apower contribution metric of a second signaling resource of the eachbeam of the plurality of beams; means for ranking, by the UE, theplurality of beams based on a ranking parameter, wherein the rankingparameter includes one of: the interference plus noise metric, or thepower contribution metric; means for selecting, by the UE, a subset ofhighest ranked beams from the plurality of beams according to results ofthe means for ranking; and means for transmitting, by the UE,identification of the subset of highest ranked beams to the serving basestation via the set of CSI resources.
 12. The apparatus of claim 11,wherein the means for ranking includes means for ranking the pluralityof beams based on the interference plus noise metric.
 13. The apparatusof claim 12, further including: means for selecting, by the UE, a secondsubset of beams from the plurality of beams based on the powercontribution metric; and means for transmitting, by the UE, a secondidentification of the second subset of beams to the serving basestation.
 14. The apparatus of claim 12, wherein the means for selectingof the subset of highest ranked beams comprises means for selectingbeams from among the plurality of beams such that each of the selectedbeams has a respective power contribution metric that exceeds apredetermined power contribution threshold.
 15. The apparatus of claim11, wherein the means for selecting of the subset of highest rankedbeams comprises means for selecting beams from among the rankedplurality of beams such that each of the selected beams has a respectiveinterference plus noise metric that exceeds a predetermined interferenceplus noise threshold.
 16. The apparatus of claim 11, wherein the meansfor transmitting further include: means for transmitting theinterference plus noise metric and the power contribution metric foreach beam of the subset of highest ranked beams.
 17. The apparatus ofclaim 11, wherein the means for measuring the first signaling resourceincludes: means for measuring a plurality of instances of the firstsignaling resource within a same transmission configuration indicator(TCI) state; and one of: means for averaging a plurality of interferenceplus noise measurements of the plurality of instances of the firstsignaling resource for the interference plus noise metric; or means forselecting a maximum interference plus noise measurement of the pluralityof instances of the first signaling resource for the interference plusnoise metric; or means for selecting a minimum interference plus noisemeasurement of the plurality of instances of the first signalingresource for the interference plus noise metric.
 18. The apparatus ofclaim 11, wherein the first signaling resource is a same resource as thesecond signaling resource.
 19. The apparatus of claim 11, wherein themeans for receiving occurs over a plurality of receiver diversitybranches at the UE, wherein the means for measuring of the interferenceplus noise metric includes one of: means for calculating an averageinterference plus noise metric of interference plus noise measurementsof each of the plurality of receiver diversity branches, wherein theaverage interference plus noise metric corresponds to the interferencephis noise metric; means for identifying a minimum interference plusnoise metric of the plurality of receiver diversity branches, whereinthe minimum interference plus noise metric corresponds to theinterference plus noise metric; means for identifying a maximuminterference plus noise metric of the plurality of receiver diversitybranches, wherein the maximum interference plus noise metric correspondsto the interference plus noise metric; or means for calculating aneffective interference plus noise metric based on a sum-capacitymeasurement of interference plus noise over the plurality of receiverdiversity branches, wherein the effective interference plus noise metriccorresponds to the interference plus noise metric.
 20. The apparatus ofclaim 11, wherein the CSI reporting configuration message specifies aquantity of beams for the UE to report in the subset of highest rankingbeams.
 21. An apparatus configured for wireless communication, theapparatus comprising: at least one processor; and a memory coupled tothe at least one processor, wherein the at least one processor isconfigured: to receive, at a user equipment (UE), a channel stateinformation (CSI) reporting configuration message from a serving basestation, wherein the CSI reporting configuration message identifies aset of CSI resources for reporting CSI of a plurality of beams by theUE; to measure, by the UE, an interference plus noise metric of a firstsignaling resource of each beam of the plurality of beams; to measure bythe UE, a power contribution metric of a second signaling resource ofthe each beam of the plurality of beams; to rank, by the UE, theplurality of beams based on a ranking parameter, wherein the rankingparameter includes one of: the interference plus noise metric, or thepower contribution metric; to select, by the UE, a subset of highestranked beams from the plurality of beams according to execution of theconfiguration of the at least one processor to rank; and to transmit, bythe UE, identification of the subset of highest ranked beams to theserving base station via the set of CSI resources.
 22. The apparatus ofclaim 21, wherein the configuration of the at least one processor torank includes configuration to rank the plurality of beams based on theinterference plus noise metric.
 23. The apparatus of claim 22, furtherincluding configuration of the at least one processor: to select, by theUE, a second subset of beams from the plurality of beams based on thepower contribution metric; and to transmit, by the UE, a secondidentification of the second subset of beams to the serving basestation.
 24. The apparatus of claim 22, wherein the configuration of theat least one processor to select of the subset of highest ranked beamscomprises configuration of the at least one processor to select beamsfrom among the plurality of beams such that each of the selected beamshas a respective power contribution metric that exceeds a predeterminedpower contribution threshold.
 25. The apparatus of claim 21, Wherein theconfiguration of the at least one processor to rank includesconfiguration of the at least one processor: to rank the plurality ofbeams based on the power contribution metric; to compare theinterference plus noise metric of each beam of the plurality of beamsagainst a predetermined interference plus noise threshold; and to selectthe subset of beams according to the interference plus noise metric ofthe each beam exceeding the predetermined interference plus noisethreshold.
 26. The apparatus of claim 21, wherein the configuration ofthe at least one processor to transmit further includes configuration totransmit the interference plus noise metric and the power contributionmetric for each beam of the subset of highest ranked beams.
 27. Theapparatus of claim 21, wherein the configuration of the at least oneprocessor to measure the first signaling resource includes configurationof the at least one processor: to measure a plurality of instances ofthe first signaling resource within a same transmission configurationindicator (TCI) state; and configuration of the at least one processorto one of: average a plurality of interference plus noise measurementsof the plurality of instances of the first signaling resource for theinterference plus noise metric; or select a maximum interference plusnoise measurement of the plurality of instances of the first signalingresource for the interference plus noise metric; or select a minimuminterference plus noise measurement of the plurality of instances of thefirst signaling resource for the interference plus noise metric,
 28. Theapparatus of claim 21, wherein the first signaling resource is a sameresource as the second signaling resource.
 29. The apparatus of claim21, wherein the configuration of the at least one processor to receiveoccurs over a plurality of receiver diversity branches at the UE,wherein the configuration of the at least one processor to measure theinterference plus noise metric includes configuration of the at leastone processor to one of: calculate an average interference plus noisemetric of interference plus noise measurements of each of the pluralityof receiver diversity branches, wherein the average interference plusnoise metric corresponds to the interference plus noise metric; identifya minimum interference plus noise metric of the plurality of receiverdiversity branches, wherein the minimum interference plus noise metriccorresponds to the interference plus noise metric; identify a maximuminterference plus noise metric of the plurality of receiver diversitybranches, wherein the maximum interference plus noise metric correspondsto the interference plus noise metric; or calculate an effectiveinterference plus noise metric based on a sum-capacity measurement ofinterference plus noise over the plurality of receiver diversitybranches, wherein the effective interference plus noise metriccorresponds to the interference plus noise metric.
 30. The apparatus ofclaim 21, wherein the CSI reporting configuration message specifies aquantity of beams for the UE to report in the subset of highest rankingbeams.